textproduct: Quad Cities

KEY MESSAGES

- Outside of a low risk of rain late Tuesday night into Wednesday, mainly dry with near normal temperatures for the remainder of the week.

- De-amplification of the flow pattern aloft by the weekend raises the prospects of potentially more systems moving through the area. This results in the possibility of rain for part of the weekend.

SHORT TERM /THROUGH WEDNESDAY/

Issued at 152 AM CDT Tue Aug 25 2026

Subtle mid level ridging and departing surface high pressure today will continue tranquil weather conditions across the area. Weak southerly flow develops across the area today with high temperatures in the lower 80s.

Tonight, a shortwave currently in the Northern Plains dives southeastward toward the Great Lakes pushing a weak cool front into the northwest counties by 12 UTC Wednesday. Weak lift and limited moisture overspread the area after 6 UTC Wednesday. Chances for showers and storms have been lowered to 20 to 30 percent mainly in the 6 to 15 UTC Wednesday window. Expecting isolated shower and storm coverage with front. This front then moves slowly eastward during the day with winds switching to northwest behind the front and increasing to 10 to 20 knots. For this reason, think that high temperatures will occur during the late morning and early afternoon.

Wednesday afternoon as the front exits our northwest Illinois counties, models show 1000 to 1500 J/KG of CAPE with around 30 knots of shear. If storms can develop ahead of the front during the afternoon, isolated severe storms will be possible east of the Mississippi River.

LONG TERM /WEDNESDAY NIGHT THROUGH MONDAY/

Issued at 152 AM CDT Tue Aug 25 2026

Wednesday night through Friday:

Northwesterly flow aloft is forecast to remain in place with surface high pressure drifting across the area. This results in weak flow across the region. High temperatures on Thursday and Friday will be in the lower to mid 80s. Dewpoints on Thursday and Friday are forecast to be in the lower to mid 60s which should feel comfortable.

Saturday through Monday:

By the weekend, de-amplification of the flow pattern aloft will occur across the CONUS. During this change a flat ridge will be centered from the southern Plains into the upper Midwest. Thus while more systems will potentially be moving through the area, they will be topping the ridge axis and would thus be at their weakest.

Any Gulf moisture for the systems has to come up through west Texas before turning northeast into the Plains.

Right now the model consensus has mainly 15-30% chances for rain Saturday through Monday with the better rain chances north of I-80. In looking at the AIGFS and AIFS, rain chances are not as good which would support a further reduction in rain chances as the week progresses.

AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/

Issued at 1202 PM CDT Tue Aug 25 2026

VFR conditions will prevail through much, if not all, of the TAF period. Southerly winds of 5-10 KTs will be seen through much of the TAF period as well, slowly shifting southwesterly after 03z ahead of an approaching cold front. Behind the cold front, winds will become northwesterly, generally after 12z Wednesday. The front will pass through between 06-15z, where we will also see low end chances for rain showers. Although, much uncertainty remains on timing and coverage. Much of the activity should remain isolated, with best chances limited to our north. Thus, opted to include a PROB30 for DBQ at this time, keeping mention out of the TAFs for the remaining terminals due to low confidence.

DVN WATCHES/WARNINGS/ADVISORIES

IA...None. IL...None. MO...None.